Collection: Undersink Water Heaters

FAQs

• How do I choose between an instant (tankless) and a storage (mini-tank) under sink water heater?

  The choice depends on your specific needs:

  • Instantaneous: Best for low-volume, continuous use. They are more energy-efficient because they only heat water on demand. They're ideal if you need a quick burst of hot water for washing hands or filling a glass, but their flow rate is limited, so they may not be suitable for filling a large sink quickly.
  • Storage: Best for higher-volume, intermittent use. They have a small tank that holds a ready supply of hot water. They're great for filling a sink with hot water for washing dishes. The downside is that the hot water supply is limited by the tank's size, and there is a small amount of standby heat loss.
• Can an under sink water heater supply hot water to more than one faucet?

  It is generally not recommended. Under sink water heaters are specifically designed as "point-of-use" devices for a single faucet or a very small number of closely located outlets. Trying to supply hot water to multiple faucets can overwhelm the unit's capacity, leading to a significant drop in water temperature and pressure. For a full bathroom or kitchen, you should consider a larger, whole-house water heater.
  

• Do under sink water heaters need professional installation?

  While some mini-tank models can be plugged into a standard electrical outlet and are relatively easy to install, it is always recommended to have a qualified plumber or electrician perform the installation. This is especially true for tankless models, which often require a dedicated circuit and high-amperage wiring. Professional installation ensures the unit is safely and correctly connected to both the water and electrical supply, and that it complies with all local building codes.

• Why is the hot water from my under sink heater not lasting long enough?

  If you have a storage (mini-tank) model and the hot water runs out too quickly, the most likely reason is that the tank's capacity is too small for your usage. For example, a 2.5-gallon unit is great for hand washing but may not be sufficient for washing a large number of dishes. In this case, you may need to upgrade to a larger tank. A less common cause could be a failed heating element or a thermostat set too low.
  

• How much can an under sink water heater save me on my utility bills?

  Under sink water heaters can save you money in two ways. First, they eliminate the "water waste" of letting the tap run while you wait for hot water to arrive from a central heater. Second, they reduce the energy lost from long pipe runs. The savings are most significant in homes where the central water heater is far from the sink, and you frequently use small amounts of hot water. While a storage model has a small standby loss, an instantaneous model has no standby loss at all, making it a very efficient choice for point-of-use applications.